Multi-plunger engine fuel oil pump



May 28, 1968 J. H. PARKS MULTI-PLUNGER ENGINE FUEL OIL PUMP 3Sheets-Sheet 1 Filed March '7, 1967 INVENTOR. JOHN H. PARKS k g Q 1* 7ATTORNEYS May 28, 1968 J. H. PARKS MULTI-PLUNGER ENGINE FUEL OIL PUMP 3Sheets-Sheet 2 Filed March 7, 1967 m 2 AA qw mm mm mm mm 8 S 0 Q O o 00o l' INVENTOR.

JOHN H. PARKS ATTORNEYS 3 mm Y a 0, mm B mq 9 mm May 28, 1968 J. H.PARKS 3,385,221

MULTI-PLUNGER ENGINE FUEL OIL PUMP Filed Marqh '7, 1967 3 Sheets-Sheet 3INVENTOR.

JOHN H. PARKS ATTORNEYS United States Patent 3,385,221 MULTI-PLUNGERENGINE FUEL OIL PUMP John H. Parks, Peoria, lll., assignor toCaterpillar Tractor (10., Peoria, Ill., a corporation of CaliforniaFiled Mar. 7, 1967, Ser. No. 621,165 1 Claim. ((11. 103-41) ABSTRACT 0FTHE DISCLOSURE An engine fuel pump assembly with one plunger for eachengine cylinder having the plungers arranged in alignment in one or twolines and individual volume setting means for each plunger included in asimple volume control linkage between a governor actuated member and theplungers.

Reference will be made to a co-pending application of Maxwell, Millerand Parks, Ser. No. 690,242, filed Dec. 13, 1967, which discloses thedetails of a governor which may be used with the fuel pump of thepresent invention.

Fuel pumps containing individual plungers and barrels in a comm-onhousing in which the pumps are immersed in fuel oil, also serving as alubricant for the moving parts, are known. It is also known to time andmeter the flow of fuel to and from the pump barrels by ports leadingthrough the plunger and valved by adjustable collars through which theplungers reciprocate. In the present invention, the pump assemblies area simple economical type with fixed timing and governor control ofvolume per stroke delivered to the engine cylinders.

It is an object of the invention to provide in such a pump a verysimple, easily adjusted means for varying the volume delivered by eachstroke of each individual pump, thereby enabling all pumps to deliveruniformly throughout the range of volume demanded by a governor.

Further and more specific objects and advantages of the invention andthe manner in which it is carried into practice are made apparent in thefollowing specification by reference to the accompanying drawings.

In the drawings:

FIG. 1 is a longitudinal vertical sectional view through a pump housingshowing pumps and controls therefor embodying the present invention;

FIG. 2 is a sectional view taken 011 the line IIII of FIG. 1;

FIG. 3 is a fragmentary detail of a portion of control mechanism shownin FIGS. 1 and 2;

FIG. 4 is a further detail of a part of the mechanism shown in FIG. 3;

FIG. 5 is a fragmentary view in the section taken on the line VV of FIG.1; and

FIG. 6 is a fragmentary section taken on the line V1- VI of FIG. 5.

Referring first to FIGS. 1 and 2, a pump housing 16 is shown asjournaling a camshaft 12 drive-n by a gear 14 which may be part of anengine timing gear train not shown. The camshaft drives the plungers ofa plurality of identical fuel oil pumps such as generally indicated at16. In the present case, there are two lines of pumps arranged at 90degrees to each other with four pumps in each line for delivering fuelin timed sequence as determined by the single camshaft to cylinders ofan eight cylinder engine. The principles of the present invention will,however, apply to a single line of pumps for an engine of any number ofcylinders as will be apparent upon reading the ensuing description.

The pumps and moving parts within the housing are immersed in fuel oilwhich is delivered to the housing by an engine driven transfer pump. Inthe present instance, the transfer pump comprises two pump gears 18 and20 shown in FIGS. 1 and 5 with the driving gear 18 keyed to the camshaft12 and both gears housed in an auxiliary side wall or cover plate 22 ofthe pump housing 10. As most clearly illustrated in FIG. 5, fuel from asource of supply not shown enters through a conduit 24 and passage 26where it is delivered by the pump gears to a passage 28 (see also FIG.6) which enters the pump housing 10.

The construction of the several pumps which are identical is best shownby the pump illustrated in cross-section at the left hand side of FIG.2. A pump plunger 30 is reciprocable within a barrel 32 welded orotherwise suitably secured to a bonnet 34 which is threaded into anopening in the pump housing and adapted for communication with thecombustion chamber of an engine cylinder. A spring check valve 36 in thebonnet closes the pump barrel and is opened to admit oil to thecombustion chamber only when pressure in the barrel attains apredetermined maximum. A spring 38 urges the plunger toward retractionfrom the barrel being disposed between a shoulde-r on the exterior ofthe barrel and a spring seat 40. The lower end of the plunger seats in acam follower comprising an apron portion 42 slidable in a suitable boreformed in the pump housing and carrying an anti-friction roller 44 forengagement with a cam surface on the camshaft 12.. When the plunge-r isretracted or in the partially retraoted position shown in FIG. 2, fuelunder moderate pressure from the fuel pump is admitted from within thehousing through a port 46 in the pump barrel so that upon rotation ofthe cam and advancement of the plunger into the barrel, the poet isclosed trapping and compressing the fluid in the chamber above theplunger until the check valve opens and fluid is directed to the engine.In this type of fuel injection mechanism, the timing of injection isdetermined by the fixed position of the port 46 and injection beginsshortly after closing of the port at the head end of the plunger. Volumeof fuel delivered per plunger stroke is, however, controlled by a spillport extending transversely through the plunger as indicated in dottedlines at 48 and communicating with a longitudinal passage 49 whichextends through the head end of the plunger. A collar 50 surrounds theplunger and closes the spill port 48 during the effective stroke.However, upon upward movement of the plunger to the position where theport 48 is uncovered, pressure at the head end of the plunger is ventedinto the housing and the check valve 36 closes. This concludes thedelivery of fuel to the combustion chamber and determines the volumedelivered per stroke so that adjustment of the collar longitudinally ofthe plunger determines the volume of fuel delivered per stroke.

This adjustment maybe accomplished manually or automatically in responseto engine requirements as sensed by an engine govern-or. A rectilinearlymovable engine governor element is illustrated at 54 in FIGS. 1 and 2and this element is extended and retracted from a governor mechanismgenerally shown at 57 in FIG. 1, the construction and operation of whichis fully disclosed in the co- .pending application of Maxwell, Millerand Parks hereinabove referred to. As disclosed in said application, thegovernor member 54 moves downwardly in response to demands foradditional fuel and in doing so swings downwardly a pair of levers 56,best shown in the detail of FIG. 3, which have pins 58 engaged in agroove 59 of the member 54. These levers are secured to a pair of shafts60, one of which is also shown in FIG. 1, and the shafts carry controlpins or links 62 extending through and rotatable with respect to theshafts. Each link has a ball like end 63 eccentrically positioned withrespect to the axis of the link as is most readily apparent in FIG. 4,so that adjustment of the link by rotation thereof varies the positionof the end 63 in a direction lengthwise of the plunger. The ends 63 ofthe links are received in notches 64 of the collars so that oscillationof the pins with their supporting shafts 60 slides the collarslongitudinally of the plungers and varies the time at which the spillports 48 are opened. For example, when the governor member 54 movesdownwardly, the shafts 60 are rocked in directions to move the pins andslide the collars upwardly, thus a greater advancement of the plungersinto the pump barrels is required before the spill ports are opened andinjection is discontinued. Conversely, upward movement of the governorelement slides the collars 50 away from the pump barrel and a lesservolume of fluid will be delivered to the engine.

In FIG. 2, a partial partition shown at 68 (see also FIG. 1) formed bygovernor housing elements is partially broken away to show the fullrelationship of one of the levers 56 with the shaft 60 and links 62. Theadjustment of the links 62 enables the attainment of equal volumedelivery by each of the several pump plungers. Upon rotartion of thelink, the effective position of the end 63 is adjusted to slightly varythe time of opening the spill port and the volume of delivery, and eachlink may be fixed in its adjusted position by tightening of a nut 67.Access to the links for adjustment is easily attained by removal of asingle cover plate 70 on the housing 10.

I claim:

1. In a multi-plunger engine fuel pump of the kind having a spill portin each plunger closed and opened during plunger strokes by a relativelystationary collar surrounding the plunger and having linkage meansoperable by a governor or the like for adjusting the collarssimultaneously on a plurality of aligned plungers to vary the volume offuel delivered per plunger stroke, the improvement which comprises meansincluded in said linkage means for effecting independent adjustment ofeach plunger to insure equal volume delivery of all plungers duringsimultaneous adjustment, said linkage means including a shaft supportedfor rocking movement, a link between the shaft and each collar, saidlink extending radially of the shaft and engaging the collar wherebyrocking of the shaft slides the collars on the plungers, each link beingrotatable and having connection with its collar at a point eccentric toits axis of rotation, and means to rotate the link and lock it in anadjusted position to determine the position of the collar with respectto the plunger.

References Cited UNITED STATES PATENTS 1,877,803 9/1932 Brown 10341.l2,779,289 1/1957 Hogeman. 2,520,856 8/1950 Schowalter 103-37 ROBERT M.WALKER, Primary Examiner.

LAURENCE V. EFNER, Examiner.

